This invention relates to conveyors, and more particularly to so-called harpoon-type conveyors suitable for transporting swarf-like materials.
A harpoon-type conveyor generally comprises one or more spaced, reciprocating drive members which usually comprise a plurality of pushing blades, or harpoon plows, normally arranged in a V-shaped, or similar configuration. The harpoon plows are attached to a conveyor rod or chain, which may be and preferably is mounted on a suitable guide member situated in a conveyor trough.
In any event, the harpoon plows are located in the trough and are adapted for reciprocating movement within the trough. Projecting members or barbs are secured to the inside surfaces of the conveyor trough and function to engage and retain the material being conveyed in the conveyor trough as the pushing blade or harpoon plow is shifted from a forward position to a rearward position during a return stroke.
These conveyors are able to handle various types of swarf-like material, e.g., metal chips, from long and stringy to fine, with or without cutting fluids that may be present. Typical conveyors of this general type are illustrated in U.S. Pat. Nos. 3,112,025, 3,175,677, 3,158,257, 3,542,187, 3,659,702, 3,799,329, and 3,882,997; copending Van Nocker U.S. application Ser. No. 716,428, filed Aug. 23, 1976, now U.S. Pat. No. 4,082,178; and German Pat. No. 1,139,068.
Conveyors of this general type are well suited for transporting metal or plastic chips or swarf generally produced during manufacturing processes with machine tools such as lathes, milling machines, drills, gear hobbers, boring mills and the like. On occasion, a conveyor may become jammed. For example, pieces may wedge between the reciprocating harpoon plows and the barbs. In such instances, the conveyor must be stopped and the jam cleared. It is important that when jams do occur that they be sensed promptly and, if possible, that automatic clearing be attempted; and if not possible, the system operation terminated in order to avoid damage to the conveyor and/or the drive system therefor.